In the free-living nematode, Turbatrix aceti, cellular protein is degraded quite quickly (half-life, 30hr.), whereas in old organisms it is degraded very slowly (half-life, 250 hr.). Therefore, it is proposed to compare proteases from young and old T. aceti with the expectation that certain of these enzymes will exist at a substantially lower level in the latter. These particular proteases are presumably involved in the breakdown of cellular proteins. The experimental procedure to be used involves an attempt to "map" the proteolytic enzymes of young organisms by chromatographic separation and to characterize the enzyme types by pH optima and by testing various additives (e.g. metals) or inhibitors (leupeptin, pepstatin). A similar regime should provide a comparison with "old" preparations. Enzymes which show a reduction of activity in the latter will be selected for further purification and characterization. Membrane bound proteases will also be checked for a possible age-related loss of activity.